Sunset Lagoon Wastewater Treatment Plant, Sunset, Louisiana

Sunset Lagoon is an advanced wastewater treatment facility located in Sunset, St. Landry Parish, Louisiana, United States. The plant serves a population of approximately 2,201 residents, reflecting a small community-scale operation typical of rural Louisiana. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 1,135.62 million gallons per year and an actual discharge volume of 492.10 million gallons per year, the facility operates well within its capacity. Under the U.S. Clean Water Act, such plants are regulated through National Pollutant Discharge Elimination System (NPDES) permits issued by the Louisiana Department of Environmental Quality, ensuring compliance with water quality standards. The treated effluent from Sunset Lagoon is discharged into local waterways that ultimately drain into the Atchafalaya River Basin, one of the largest river swamps in the United States. This basin supports diverse aquatic life and provides critical habitat for migratory birds and fish species. The plant's advanced treatment helps protect downstream water quality in this ecologically significant region.

Sunset Lagoon discharges into the Atchafalaya River Basin, a vast floodplain system that flows into the Atchafalaya Bay and eventually the Gulf of Mexico. This basin is ecologically sensitive, supporting a rich diversity of fish, shellfish, and waterfowl. The advanced treatment at Sunset Lagoon reduces nutrient loading, helping to mitigate hypoxia in the Gulf of Mexico.